In the above-identified patent a machine is disclosed in which whole eviscerated poultry carcasses are introduced to a conveyor mechanism which carries each carcass into successive engagement with a series of rotary cutters which sever the carcass into the desired number of portions including, if desired, splitting the carcass in half and removing the breast meat.
Machines of this type have been operated with great success insofar as making it possible for a single unskilled operator, working with a single automatic machine, to sever poultry into a number of portions, such as that known as the "Kentucky Fried Chicken" nine-piece cut which previously required the services of a skilled butcher or, in the case of unskilled workers, entailed the use of a number of separate machines positioned along an assembly line at as many as five different stations, each of which required the services of a separate worker.
However, in the case of the machine disclosed in the above-identified patent, it has been found that as a result of the high-speed of rotation of the various cutters, operating at speeds of 3,000 RPM or more, the conventional non-friction bearings are subject to excessive failure after only a relatively short period of use.
This may be due to the fact that it is necessary to provide sealed bearings packed with a small supply of grease in order to maintain proper sanitary conditions. It is obviously impossible to use bearings which require lubricating oil continuously supplied under pressure since, even if the lubricant were non-toxic, it would necessarily come in contact with the food and spoil the taste.
The conditions under which such a machine must operate may also contribute to bearing failure. In order to preserve optimum temperature conditions, in an experimental installation the cutting machine was placed in a "cold room" used for the temporary storage of the poultry carcasses received from the wholesaler, and cutting operations, as necessary, were performed at the usual low temperatures maintained in the storage room.
A concomittant cause of bearing detereoration under those circumstances was the necessary for keeping the rotary cutters bathed in a water spray. The bearings supporting the cutters were therefore continually in contact with water thrown off from the cutters. It is therefore theorized that the frequent temperature changes due to intermittent operation of the machine in a moisture saturated atmosphere and idleness at low temperature caused excessive condensation within the conventional non-friction bearings leading to their premature breakdown.
Not only do the conventional sealed bearings have a relatively short life of only two or three months, even in intermittent use, they become increasingly noisy prior to eventual failure and producing an excruciating whining noise as they approach the end of their usefulness which noise is environmentally intolerable.
Since there may be as many as seven, or more, cutters in a single machine, and the failure of only a single bearing requires the shutdown of the entire machine for several hours, with disassembly and reassembly of a bearing whenever the shutdown occurs it will be realized that each of the bearings has represented a weak link in an otherwise reliable chain.